Distilling petroleum residuum



H. V. ATWELL May 3, 1932.

DISTILLING PETROLEUM RESIDUUM Filed March 15, 1924 Patented May 3, 1932UNITED STATES PATENT OFFICE HAROLD V. ATWELL, OF WRITING, INDIANA,ASSIGNOR T'O STANDARD OIL COMPANY, OF WHITING, INDIANA, A CORPORATION OFINDIANA DISTILLING PETROLEUM RESIDUUM Application filed March 15, 1924.Serial No. 699,459.

This invention relates to the production of useful hydrocarbon oilproducts from heavy residual pitches derived, for example, by the steamdistillation of crude petroleum oils.

The present invention is particularly use ful in the handling of theheavy pitch residues resulting from a continuous steam distillation ofcrude or reduced crude oils to bot toms con-responding, for example, toabout 15% or less than 15% on oils of the character of Mid Continentcrude oils. Such residues are normally very viscous or solid at ordinarytemperatures, have a flash point above 500 F, and their furtherdecomposition by destructive distillation is attended by many practicaldiificulties. In the specific embodiment of this invention hereinafterfully disclosed, the coking or dry distillation of such residues isefl'ectively and economically accomplished by a continuous process. Theinvention will be more fully understood by the reference to theaccompanying drawing, in which is shown somewhat diagrammatically, andpartly in section, apparatus suitable for carrying the invention intoeifect.

Referring more particularly to the draw ing, the numeral 5 indicates asupply pipe, by means of which the residue to be treated is brought intothe apparatus, being preferably preheated. The supply pipe 5 enters thechamber of a combustion furnace 6, which may suitably have a cylindricalmasonry or fire brick Wall section 7 through which extend numerousspaced openings 8. Surrounding the masonry wall section is a jacket 9,an inflammable as mixture being introduced into this ja ket through apipe 10. The perforated wall section 7 is lined by broken refractorymaterial, for example, broken fire brick, providing a perforaterefractory lining, this lining 11 being held in position by a lining ofa grid or perforated sheet, of a suitable resistant metal, e. g.nichrome, etc., gauze or cloth 12. The brick section 7, lining 11 andgauze 12 collectively provide the defining wall of the aforesaid chamberof the combustion furnace 6. The inflammable mixture introduced .at 10passes through the perforations 8 in the wall of the furnace andundergoes surface or flameless combustion in the refractory lining 11,the rate of supply being preferably so controlled as to keep the zone ofcombustion as near as possible to the inner surface of this layer ofmaterial. The gaseous mixture may be ignited in any suitable manner,such as by introducing a flaming torch through the flue 23 to theinterior of the chamber and through a suitable opening in the screen 12.The mixture of combustible gases may then be introduced through the line10, the velocity of the mixture being such that surface combustion willoccur in the small spaces in the lining 11. It is readily apparent thatother heating means than that above described may be employed; thus thelining 12 in the form of a suitable metallic grid, may be employed as anelectric heating element and an inert gas, such as flue gas, nitrogen,carbon dioxide, superheated steam or the like may be forced in from thejacket 9. The preheated oil, introduced through the pipe 5, is broken upor atomized by the spray head 13, and in a finely subdivided form, isbrought to a high temperature, say 800 to 1000 F., by the heat appliedand is likewise intermixed with the combustion gases entering the spacewithin the furnace lining 12. The passage of the gases through thisfurnace lining prevents adherence of coke thereto. The coke and productsof distillation, together with ad mixed combustion gases, pass throughtheshort conduit 14 into the settling chamber 15, which isdiagrammatically shown, and may be constructed as any suitable effectiveform of separator. Coke deposited in this separating chamber collects inits conical lower portion 16, a baflie 17 being provided to prevent itspassage through the vapor exit 18. Vapors and gases pass out through thevapor pipe 18, condensate or entrained liquid deposited therein bcingdrawn off through the draw-off pipe 19, for example, for examination ortesting. Vapors and condensate pass out of the vapor passage 18 throughpipe 20 and pass through a suitable condenser 21, which may be watercooled if desired. From the condenser 21 the products pass into a riseror gas separator 22, condensates passing out through pipe 23 anduncondensed gases being withdrawn from the top.

In carrying out the process, it has been found convenient to control theheating in the furnace or heating chamber by the temperature conditionsprevailing at its exit, that is, in the passage 14 or substantially atthe inlet to the chamber 15. It has been found that satisfactory yieldsof distillation products may be obtained when this temperature is from800 to 1200 F. The oil may suitably be preheated before injection intothe furnace 6 to a temperature of 500 to 700 F. The atomizing or spraynozzle 13 is so constructed that the column of spray thrown by it doesnot impinge upon the interior Walls of the furnace, that is, upon thelining 12. If it is not desired to employ the entire body of combustiongases in the manner described, a portion thereof may be diverted, forexample, through an outlet 23, directly through the stack (not shown)The distillation of the finely subdivided residuum is very rapid and thecoke formed as a result ofiits distillation is in finely divided form,the greater portion thereof separating out in a separator 15.

The following example illustrates a method of carrying out the presentinvention. The residuum handled may be, for example, a 14 B. MidContinent crude residuum having a flash point of about 525 F. The oil,preheated, for example, to a temperature of about 600 F., is sprayedinto the furnace through the pipe 5 and the nozzle 13. The combustionchamber is heated by inflammable gas introduced through the pipe 10,inert combustion gas being mixed with the finely divided oil in theinterior of the furnace within the lining 12 and passing out through thevapor passage 14, where a temperature of 1000 to 1100 F. is produced.Liquid distillate products are formed to the extent of about to theseproducts having a Viscosity of about 128 sec. Saybolt at 210 F. and aBaum gravity of 18 to'20. An average product shows an initial boilingpoint of 380 to 400 F. and approximately 80% off at 750 F.

I claim:

1. The method of distilling anddecomposing heavy petroleum residues forthe production of coke and lower boiling oils therefrom, which comprisesspraying such residues in finely divided form through a coking chamberhaving a perforated wall, internally heating the body of the perforatedwall of the chamber, introducing inert gases into the chamber throughthe perforations in said heated wall into the chamber, whereby the gasesare heated and impart heat to the oil residues therein suflicient toeffect coking of the individual finely divided portions of such residueand the production of lower boiling oils in vaporous form, passin thefinely divided coke and vaporous pro ucts to an independent, separate,unheated chamber, separately withdrawing the vaporous products from saidsecond chamber, and cooling the vapors to condense low boiling oilstherefrom.

2. The method of distilling and decomposing heavy petroleum residues forthe production of coke and lower boiling oils therefrom, which comprisesspraying such residues in finely divided form through a chamber,effecting combustion of fuel within combustion spaces comprising amaterial part of the area of the body of the wall of said chamber,introducing the gases produced by such oombustion into said chamber,whereby the gases impart heat to the oil residues therein sufficient toeffect coking of the individual finely divided portions of such residuesand the production of low boiling oils in vaporous form, passing thefinely divided coke and vaporous products to an independent, separate,unheated chamber, separately with drawing the vaporous products fromsaid second chamber, and cooling said vapors to condense low-boilingoils therefrom.

3. The method of distilling and decomposing petroleum residues for theproduction of coke and low boiling oils therefrom, which comprisesspraying such residues in finely divided form through a chamber,introducing highly heated gaseous products of combustion into saidchamber through perforations distributed over substantially the en tireinterior area of the walls of said chamber to heat said finely dividedresidues to between about 800 F. and about 1200 F. and effect a cokingof such residues and the production of low boiling oils in vaporousform, passing the coke and vaporous products to an independent,separate, unheated chamber, separately withdrawing the vaporous productsfrom said chamber, and cooling said vapors to condense low boiling oilstherefrom.

4. The method of distilling and decomposing heavy petroleum residues forthe production of coke and low boiling oils therefrom, which comprisesspraying such residues in finely divided form through a chamber,effecting combustion of fuel within the body of the wall of said chamberand introducing into the chamber the highly heated gaseous products ofcombustion through minute perforations occupying a substantial part ofthe inner aea of said walls, to heat said finely divided residues tobetween about 800 F. and 1200 F. to effect coking of the said residueand the production of low boiling oils in vaporous form, passing thecoke and vaporous products to an independent separate unheated chamber,separately withdrawing the vaporous products fom said second chamher,and cooling said vapors to condense lower boiling oils therefrom.

5. In apparatus for distilling and decomposing heavy oil residues forthe production of coke and lower boiling oils, a chamber havin aperforate wall, means for assing finely su -divided oil residues througsaid chamber, means for internally heating the body of the perforatedwall of said chamber, means for forcing heated inert gases into saidchamber through the perforations in the wall of the said chamber wherebythe gases impart heat to the oil residues within the said chamber toeffect coking of the finely divided par ticles of residues passingtherethrough and the production of lower boiling oils in vaporous form,an independent unheated separating chamber, means for passing the fineldivided coked residues and vaporous pro ucts from said coking chamber tosaid separating chamber, means for separately withdrawing vaporouspetroleum products from said separating chamber, and means forcondensing said Withdrawn vaporous products.

6. In apparatus for distilling and decomposing heavy oil residues forthe production of coke and lower boiling oils, a coking chamber providedwith a plurality of combustion spaces in a material part of the innerarea of its wall which communicates with the interior of said chamber,means for passing finely sub-divided oil residues through said chamber,means for supplying suitable combustible material into said combustionspaces to produce combustion therein, whereby the products of combustionflow from said combustion spaces into the chamber and impart heat to theoil residues passing therethrough to efiect coking of said residue andthe production of lower boiling oils in vaporous form, an independentunheated separating chamber, means for passing the coked residues andsaid vaporous products to said separating chamber, means for separatelywithdrawing vaporous products from said separating chamber, and meansfor condensing the withdrawn vaporous products.

HAROLD V. ATWELL.

